生物炭与有机肥对菜田土壤氨氧化菌丰度的影响

Effects of Biochar and Organic Fertilizer on the Abundance of Ammonia Oxidizer in Vegetable Production Soil

通过土壤培育试验,运用定量PCR技术,研究了添加生物炭和有机肥对土壤氮营养及氨氧化古菌(AOA)和氨氧化细菌(AOB)丰度的影响。结果表明,土壤培育时间、有机肥显著增加硝态氮的含量(P<0.001),促进硝化作用;生物炭通过抑制有机氮矿化作用降低硝化作用,106d时生物炭处理的硝态氮、可溶性总氮含量低于没有生物炭的处理(P<0.05),并且中和了有机肥对矿化作用的促进效应。随着处理时间的延长,生物炭促进氨氧化菌群的丰度,AOA丰度的提高较AOB显著,且AOA丰度的变化与硝态氮含量的变化呈正相关。因此认为AOA是土壤中氨氧化作用的主要驱动力,且生物炭与有机肥主要对AOA的丰度产生影响。

A 106-days soil incubation and qPCR based on amoA genes were carried out to study the effect of biochar and organic fertilizer on the abundance of soil ammonia-oxidizing bacteria （AOB）and ammonia- oxidizing archaea （AOA）. The results showed organic fertilizer and biochar significantly increased and decreased nitrate content（P〈0. 05）, respectively. Thus we suppose biochar inhibited nitrification which is the process of turning ammonium to nitrate, while organic fertilizer had opposite effects. In addition, biochar decreased the inorganic nitrogen released from mineralization of organic nitrogen, indicating biochar weakened nitrification by inhibiting mineralization. Biochar increased the abundance of AOB and AOA over time,while the promoting effect of biochar on AOA abundance was higher than AOB. AOA were more abundant than AOB,and the dynamic NO3--N content was positively correlated with AOA abundance（P〈 0. 001）, indicating AOA might be the main driver of nitrification.